1. Field of the Invention
The present invention relates generally to medical apparatus and methods. More particularly, the present invention relates to methods and systems for vascular surgery, including intraluminal vein harvesting and fistula creation.
Cardiac and peripheral vascular bypass surgery commonly employs veins harvested from the patient undergoing surgery, usually obtained by autologous vein harvesting procedures. Vein harvesting commonly relies on making a long skin incision to expose the length of vein which is to be excised and removed. Such exposure of the vein allows for dissection and division of the veins which branch from the portion of vein being removed. The greater saphenous vein in the leg is most commonly used, followed by the lesser saphenous vein in the leg and the basilic and cephalic veins in the arm.
Such long incisions made for vein harvesting are highly traumatic and problematic for a number of reasons. First, patients requiring bypass surgery often suffer from other diseases, such as diabetes, obesity, malnutrition, which may impede healing and increase the risk of infection of the skin incisions. Additionally, the cosmetic scarring which results from the long incisions is of concern to many patients.
To partly overcome these drawbacks, systems for the endoscopic harvesting of veins have been developed. Such systems, presently available from suppliers such as Ethicon and General Surgical Innovations, rely on introduction of endoscopic apparatus through an incision at one end of the vein segment to be removed. The apparatus includes a viewing scope, a mechanism for dissecting the vein from the surrounding tissue bed, and additional mechanisms for dissecting the vein from side branches to facilitate removal. Other systems, such as that available from Guidant Corporation, use gas insufflation to create a working space around the vein and rely on percutaneously introduced instruments for excising the vein. In all cases, the systems are expensive, cumbersome to use, and still traumatic to the patient.
Arteriovenous fistulas (AVFs) are another difficult vascular surgery which require long incisions and extensive surgical dissections. In particular, autologous AVF procedures in the upper arm between the brachial artery and the basilic vein can be problematic. The present techniques generally require that a patient be placed under general anesthetic for vein transposition and anastomosis.
For these reasons, it would be desirable to provide improved vein harvesting apparatus and methods for performing vascular surgeries, including vein harvesting and AVF procedures. Such improved surgeries would preferably be minimally traumatic to the patient, do not require long skin penetrations or incisions at points between the two ends of the vein segment being removed, permit selective excision of the venous side branches and optional sealing of the side branches, and provide a vein segment which is maintained relatively intact, allows for valve removal and can be used for bypass grafting AVF formation, or other purposes with minimal additional preparation. It would be further desirable if the systems and methods were also useful for vein stripping and removal for treatment of varicose veins and other conditions. The system and methods should optionally permit endoscopic visualization of the vein while it is being removed and remove relatively long vein segments with a single device deployment. At least some of these objectives will be met by the inventions described hereinafter.
2. Description of the Background Art
Intraluminal vein removal and modification devices are described in U.S. Pat. Nos. 6,165,172; 6,030,396; 6,013,073; 5,843,104; 4,528,982; 3,788,325; 3,568,677; 3,185,155; 3,045,676; 2,779,334; and PCT Publication WO 00/45691. Endoscopic and extraluminal vein removal devices are described in U.S. Pat. Nos. 6,022,313; 5,817,013; 4,793,346; and Re. 36,053. Patents relating to vein harvesting assigned to General Surgical Innovations include U.S. Pat. Nos. 6,196,968; 6,077,289; 6,068,639; 5,993,412; 5,968,066; 5,944,734; 5,899,913; and 5,853,417. Patents relating to vein harvesting assigned to Ethicon include U.S. Pat. Nos. 6,193,653; 5,928,138; 5,922,004; 5,902,315; and 5,667,480. Use of an endoscopicedly harvested saphenous vein to transposition and anastomosis to the femoral artery is suggested in Illig et al. DMID: 12044427.